1. Field of the Invention
The present invention relates to engine control devices, and particularly relates to mechanisms designed to remotely control the throttle, shift and emergency stop functions of marine engines.
2. Description of the Prior Art
A number of remote control units for marine engines have been developed in the prior art. The most widely used of these control units include a remote housing and a single control handle. The control handle is connected to the throttle and shift mechanisms of the engine by throttle and shift cables. The control unit also may include electrical switches which are connected to the electrical system of the engine. These remote control units permit operation of only the shift mechanism (forward or reverse) during the first portion of rotation of the control handle and then, during the last portion of rotation, permit control of only the throttle mechanism. Such arrangements are disclosed in the following U.S. Pat. Nos. 3,301,084 to Boda; 3,309,938 to Pervier; and 4,027,555 to Rauchle, et al.
The United States patents to Pervier and Rauchle, et al, also describe a "warm up" or "throttle only" button positioned at the base of the control handle. This button disengages the shift mechanism and permits operation of only the throttle mechanism upon rotation of the handle. One disadvantage of such "throttle only" mechanisms is that they utilize a driving key which moves axially to engage or disengage a shift mechanism. This requires an elongated slot which is difficult and costly to manufacture.
One known prior control also includes a neutral lock mechanism. The neutral lock mechanism locks the control handle in a neutral position. Included in the neutral lock mechanism is a release lever or trigger to unlock the control handle. When unlocked, the control handle can be rotated to operate the shift and throttle mechanisms. The problem with this known prior control is that the trigger is on the lower surface of a T-shaped control handle. This position of the trigger is difficult to operate with a natural closing of the hand over the T-shaped control handle. This prior known control also was limited to a vertical handle position for neutral.
Marine engines have also used a safety stop switch as a separate accessory. A safety stop switch is used to stop the engine in an emergency. One suitable prior safety stop switch used a spring loaded push switch which when depressed permits the engine to operate. A cap is normally positioned on the switch to permit the engine to operate. The cap is connected to the operator so that if the operator is thrown from the control station the lanyard pulls the cap free of the switch causing the engine to stop. The safety stop switch must be continually depressed to allow a passenger to restart and run the engine in order to rescue the operator.
U.S. Pat. Nos. 2,588,650; 2,729,984; 2,826,283; 2,919,772; 2,975,653; 3,023,869; 3,165,941; 3,208,300; 2,702,615; 2,737,822; 2,884,109; 2,960,199; 2,986,044; 3,043,159; 3,202,125; 3,143,994; 2,705,485; 2,762,606; 2,907,412; 2,966,969; 2,987,152; 3,127,785; 3,204,732; and 3,160,027 describe prior remote control units for marine engines. These patents describe one method for absorbing unwanted throttle movement during shifting. This is accomplished by a spring attached to a control cable anchor point. When the control handle is moved for shifting, the spring maintains the idle throttle position until the shift motion is completed. Although satisfactory, it is not suitable for a compact design.